This invention relates generally to catheters for right coronary arteries and more particularly to a preformed, torqueable guide or diagnostic catheter that has a distal segment to abut an inside surface of an ascending aorta and that also has a preformed three dimensional distal portion to facilitate entry of a distal tip into the ostium of a right coronary artery extending from the ascending aorta.
The use of catheters in diagnosing and treating vessels in a human body is well known. One particular known therapeutic use of catheters is in performing percutaneous translumenal coronary angioplasty (PTCA). One technique for performing PTCA in a right coronary artery includes inserting a guide catheter into a femoral artery and advancing the guide catheter such that its distal tip moves through that artery, up the descending aorta, and ultimately into the ostium of the right coronary artery. A balloon catheter is then pushed through the guide catheter into the right coronary artery for use in known manner. As an example of a diagnostic use, a diagnostic catheter can be similarly placed and then used to conduct a radiopaque dye injected in known manner.
There are known types of catheters designed for the right coronary artery. However, there remains the need for a new type of catheter that can be readily used with different right coronary artery morphologies found in human patients. There is the particular need for a preformed, torqueable guide or diagnostic catheter to which torque can be applied from the proximal end and transmitted to the distal end and which has a preformed three-dimensional distal end portion having a tip and shaped such that the tip readily enters the ostium of the right coronary artery upon the initial placement of the catheter or when suitable torque is applied to the proximal end of the catheter.
The present invention meets the aforementioned needs by providing a novel and improved catheter for a right coronary artery and especially a preformed, torqueable guide or diagnostic catheter to selectively engage the ostium of a right coronary artery in a human. The catheter of the present invention has a distal tip that can be readily placed in the ostia of right coronary arteries across a range of morphologies for such arteries. The structure of the catheter is such that it allows a relatively long, atraumatic tip to be used while diminishing the rotational manipulation that may be needed to engage the tip in the ostium, which provides for easier, less traumatic use of the catheter.
Such a preformed, torqueable guide or diagnostic catheter as defined by the present invention to selectively engage the ostium of a right coronary artery in a human comprises a proximal shaft having a proximal end to receive manipulation by a user outside a human body in which the catheter is used, wherein the proximal shaft transmits torque applied at the proximal end. This catheter further comprises a distal shaft extending from the proximal shaft opposite the proximal end of the proximal shaft such that the distal shaft is responsive to torque transmitted by the proximal shaft. The distal shaft includes a preformed support section having at least a segment thereof which abuts an interior surface of the ascending aorta of the human body when the catheter is in place within the human body. The distal shaft also includes a preformed ostium entry section extending from the support section. In at least an initial position of the catheter outside the human body with the support section of the catheter in a plane parallel to a frontal plane of the body, the ostium entry section of a preferred embodiment lies posteriorly of that plane when the preformed ostium entry section extends rightwardly, relative to the human body, from the preformed support section.
A catheter for a right coronary artery in accordance with the present invention can also be defined as comprising: a proximal shaft having a proximal end to receive manipulation by a user outside a human body in which the catheter is used; and a distal shaft extending from the proximal shaft opposite the proximal end of the proximal shaft. The distal shaft includes a preformed support section to abut a posterior interior surface of the ascending aorta of the human body. This support section includes: a transition segment connected to the proximal shaft at a first bend initially forming an included angle of between 135xc2x0 and 175xc2x0, wherein the transition segment is initially substantially linear; and an abutment segment connected to the transition segment at a second bend initially forming an included angle of between 135xc2x0 and 175xc2x0, wherein the abutment segment is initially substantially linear. The distal shaft also includes a preformed ostium entry section extending from the preformed support section. The preformed ostium entry section includes: a first segment connected to the abutment segment at a third bend initially forming an included angle of between 80xc2x0 and 160xc2x0, wherein the first segment is initially substantially linear; a second segment connected to the first segment at a fourth bend initially forming an included angle of between 100xc2x0 and 170xc2x0, wherein the second segment is initially substantially linear; and wherein the first and second segments are initially offset from an imaginary plane defined by the transition and abutment segments of the preformed support section. In a particular implementation, the first segment is disposed at an initial angle of 130xc2x0 to 180xc2x0 relative to one such imaginary plane; and the second segment is disposed at an initial angle of 120xc2x0 to 180xc2x0 from a plane defined by the first segment and the abutment segment of the preformed support section. In a more specific implementation, the transition segment has a length between 20 millimeters and 80 millimeters, the abutment segment has a length between 10 millimeters and 40 millimeters, the first segment has a length between 10 millimeters and 40 millimeters, and the second segment has a length between 10 millimeters and 40 millimeters. The second segment terminates at a distal tip which enters the ostium of a right coronary artery when the catheter is properly placed in the human body. There may be another bend between the transition segment and the proximal shaft of between 140xc2x0 and 180xc2x0 and another bend between the abutment segment and the transition segment of between 140xc2x0 and 180xc2x0.
Therefore, from the foregoing, it is a general object of the present invention to provide a novel and improved catheter for a right coronary artery and especially a preformed, torqueable guide or diagnostic catheter to selectively engage the ostium of a right coronary artery in a human. Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art when the following description of the preferred embodiments is read in conjunction with the accompanying drawings.